Based on ZrO2/graphene/ZrO2 Q-switched mid-infrared Er3+:ZBLAN fiber laser

ZrO2 nanoparticles with an average size of similar to 40nm are prepared by an electrical arc discharge method. Here, we fabricated a saturable absorber mirror (SAM) by spin-coating ZrO2, graphene and ZrO2 onto a homemade high-reflective mirror. Stable Q-switching operation in Er3+:ZBLAN fiber laser is achieved by using the as-prepared ZrO2/graphene/ZrO2 SAM. Compared with ZrO2 SAM, the ZrO2/graphene/ZrO2 SAM has a lower Q-switching threshold and wider range of repetition rates. The maximum average output power of 285 mW is obtained with the repetition rate of 106.61 kHz, pulse width of 0.908 mu s and timing jitter of 0.514% at the pump power of 4.84 W by using the ZrO2/graphene/ZrO2 SAM.